1 files changed, 147 insertions, 0 deletions
diff --git a/ioreplay/src/datas/rbuffer.c b/ioreplay/src/datas/rbuffer.c
new file mode 100644
index 0000000..c019e6c
--- /dev/null
+++ b/ioreplay/src/datas/rbuffer.c
@@ -0,0 +1,147 @@
+// Copyright 2018 Mimecast Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "rbuffer.h"
+
+rbuffer_s *rbuffer_new(const int size)
+{
+    rbuffer_s *r = Malloc(rbuffer_s);
+
+    r->size = size;
+    r->read_pos = size-1;
+    r->write_pos = 0;
+    r->ring = Calloc(size, void*);
+
+    Mset(r->ring, 0, size, void*);
+
+    return r;
+}
+
+void rbuffer_destroy(rbuffer_s *r)
+{
+    if (r) {
+        free(r->ring);
+        free(r);
+    }
+}
+
+bool rbuffer_insert(rbuffer_s* r, void *data)
+{
+    if (r->write_pos == r->read_pos)
+        // Ring buffer is full
+        return false;
+
+    r->ring[r->write_pos] = data;
+    r->write_pos = (r->write_pos+1) % r->size;
+
+    return true;
+}
+
+bool rbuffer_has_next(rbuffer_s* r)
+{
+    sig_atomic_t read_pos = (r->read_pos+1) % r->size;
+
+    if (read_pos == r->write_pos)
+        // No more items to read, buffer is empty
+    {
+        return false;
+    }
+
+    return true;
+}
+
+void* rbuffer_get_next(rbuffer_s* r)
+{
+    sig_atomic_t read_pos = (r->read_pos+1) % r->size;
+
+    if (read_pos == r->write_pos)
+        // No more items to read, buffer is empty
+    {
+        return NULL;
+    }
+
+    void *data = r->ring[read_pos];
+    r->ring[read_pos] = NULL;
+    r->read_pos = read_pos;
+
+    return data;
+}
+
+void rbuffer_print(rbuffer_s* r)
+{
+    Put("rbuffer_s (%p):", (void*)r);
+    Put("\tsize: %d", (int)r->size);
+    Put("\tread_pos: %d", r->read_pos);
+    Put("\twrite_pos: %d", r->write_pos);
+    Out("\toccupied slots: ");
+    for (int i = 0; i < r->size; ++i)
+        if (r->ring[i]) {
+            Out("%d:%p ", i, r->ring[i]);
+        }
+    Out("\n");
+}
+
+void rbuffer_test(void)
+{
+    rbuffer_s *r = rbuffer_new(5);
+    assert(NULL == rbuffer_get_next(r));
+
+    assert(rbuffer_insert(r, (void*)1));
+    assert(rbuffer_insert(r, (void*)2));
+    assert(rbuffer_insert(r, (void*)3));
+    assert(rbuffer_insert(r, (void*)4));
+    assert(!rbuffer_insert(r, (void*)5));
+    rbuffer_print(r);
+
+    assert(rbuffer_has_next(r));
+    assert(1 == (long) rbuffer_get_next(r));
+    assert(2 == (long) rbuffer_get_next(r));
+    assert(3 == (long) rbuffer_get_next(r));
+    assert(4 == (long) rbuffer_get_next(r));
+    assert(!rbuffer_has_next(r));
+    assert(NULL == rbuffer_get_next(r));
+
+    assert(rbuffer_insert(r, (void*)1));
+    assert(1 == (long) rbuffer_get_next(r));
+    assert(rbuffer_insert(r, (void*)2));
+    assert(2 == (long) rbuffer_get_next(r));
+    assert(rbuffer_insert(r, (void*)3));
+    assert(3 == (long) rbuffer_get_next(r));
+    assert(rbuffer_insert(r, (void*)4));
+    assert(4 == (long) rbuffer_get_next(r));
+    assert(rbuffer_insert(r, (void*)5));
+    assert(5 == (long) rbuffer_get_next(r));
+    assert(NULL == rbuffer_get_next(r));
+    rbuffer_print(r);
+
+    assert(rbuffer_insert(r, (void*)1));
+    rbuffer_print(r);
+    assert(rbuffer_insert(r, (void*)2));
+    assert(1 == (long) rbuffer_get_next(r));
+    rbuffer_print(r);
+    assert(rbuffer_insert(r, (void*)3));
+    assert(2 == (long) rbuffer_get_next(r));
+    rbuffer_print(r);
+    assert(rbuffer_insert(r, (void*)4));
+    assert(3 == (long) rbuffer_get_next(r));
+    rbuffer_print(r);
+    assert(rbuffer_insert(r, (void*)5));
+    rbuffer_print(r);
+    assert(4 == (long) rbuffer_get_next(r));
+    rbuffer_print(r);
+    assert(5 == (long) rbuffer_get_next(r));
+    assert(NULL == rbuffer_get_next(r));
+
+    rbuffer_destroy(r);
+}